Menstrual cycle associated changes in hormone-related gene expression in oestrogen receptor positive breast cancer

Ben P Haynes,Maria Afentakis,Mark Sibbering,Mark Clemons,Anthony Skene,Abigail Evans,C Leland Rogers ,Qiong Gao,Siobhan Laws,Ophira Ginsburg,Caroline Osborne,Ian Smith ,Chris Holcombe,Pham Thi Han,Ta Van To,Lubna Noor,Pham Hong Khoa,Nguyễn Văn Định ,Richard Buus,Elizabeth Folkerd,Le Hong Quang,Mitch Dowsett

doi:10.1038/s41523-019-0138-2

Abstract

The major changes in hormone levels that occur through the menstrual cycle have been postulated to affect the expression of hormone-regulated and proliferation-associated genes (PAGs) in premenopausal ER+ breast cancer. Whilst previous studies have demonstrated differences in gene expression, here, we investigated if there are within patient changes in the expression of oestrogen- and progesterone-regulated genes (ERGs and PRGs) and PAGs in ER+ breast cancer during the menstrual cycle. Samples from 96 patients in two independent prospective studies of the effect of menstrual cycle on ER+ breast cancer were used. Plasma hormone measurements were used to assign tumours to one of three pre-defined menstrual cycle windows: W1 (days 27–35 and 1–6; low oestradiol and low progesterone), W2 (days 7–16; high oestradiol and low progesterone) and W3 (days 17–26; intermediate oestradiol and high progesterone). RNA expression of 50 genes, including 27 ERGs, 11 putative PRGs and seven PAGs was measured. The AvERG (geomean of PGR, GREB1, TFF1 and PDZK1) was used as a composite measure of ERG expression and showed significant changes between the three windows of the menstrual cycle increasing over 2.2-fold between W1 and W2 and decreasing between W2 and W3 and between W3 and W1. Proliferation gene expression also varied significantly, following the same pattern of changes as ERG expression, but the changes were of lower magnitude (1.4-fold increase between W1 and W2). Significant changes in the expression of eight individual ERGs, including GREB1, PGR and TFF1, and two PAGs were observed between W1 and either W2 or W3 with all genes showing higher levels in W2 or W3 (1.3–2.4-fold; FDR 0.016–0.05). The AvProg, a composite measure of PRG expression, increased significantly (1.5-fold) in W3 compared to W1 or W2 but no significant changes were observed for individual PRGs. In conclusion, we observed significant changes in ERG, PRG and PAG expression in ER+ breast tumours during the menstrual cycle that may affect the assessment and interpretation of prominent biomarkers (e.g. PgR) and commonly used multigene prognostic signatures in premenopausal ER+ breast cancer.

Highlights

In premenopausal women, oestrogen receptor positive (ER+) disease constitutes over 80% of breast cancers.[1]
Cluster A was enriched for samples taken in W3 (24% W1, 24% window 2 (W2), 52% W3) and showed the lowest relative expression of proliferation-associated genes (PAGs), high expression of most expression of oestrogen-regulated genes (ERGs) and high progesterone-regulated gene (PRG) expression
We have previously reported significant differences in the expression of ERGs, PAGs and the PRG, RANKL, in ER+ tumours in a retrospective study that related to the major changes in hormone levels that occur during the menstrual cycle.[9,10]

Summary

Introduction

Oestrogen receptor positive (ER+) disease constitutes over 80% of breast cancers.[1]. Short-term withdrawal of oestrogens using an aromatase inhibitor for two weeks between a woman’s diagnosis and surgery has been used to assess the oestrogen dependence of ER+ breast cancers.[2,3,4,5] it is not feasible to conduct a similar pharmacological pre-surgical test in premenopausal patients as the drugs used, tamoxifen or gonadotrophin releasing hormone agonists, often display early biochemical “flare” which would obscure molecular changes over the first few weeks.[6,7] As an alternative way of measuring a tumour’s oestrogen-dependency in the premenopausal setting, we hypothesised that if there are predictable and consistent differences in the expression of oestrogen-regulated genes (ERGs) and proliferation-associated genes (PAGs) in hormone-responsive ER+ breast tumours in premenopausal women due to the large variations in plasma concentrations of oestrogen (c.100pM to c.1000pM) and progesterone >50 nM) during the menstrual cycle, the absence of such change could signify hormone insensitivity This was driven by the observation that the expression of ERGs in ER+ breast tumours correlated strongly with circulating levels of oestradiol in postmenopausal women.[8]

Methods

Results

Conclusion